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  1. MariaDB Server
  2. MDEV-36315

Inconsistent query result caused by index

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    Description

      I run the following cases, which are expected to return the same query result.

      -- case 1
      		 
      CREATE TABLE t1 (c1 TEXT) ENGINE=InnoDB;
      		 
      INSERT INTO t1 (c1) VALUES ('a');
      		 
      SELECT c1 FROM t1 WHERE CAST(c1 AS BINARY(7)) NOT IN (SELECT c1 FROM t1); -- {a}


      -- case 2
      		 
      CREATE TABLE t1 (c1 TEXT, UNIQUE (c1(1))) ENGINE=InnoDB;
      		 
      INSERT INTO t1 (c1) VALUES ('a');
      		 
      SELECT c1 FROM t1 WHERE CAST(c1 AS BINARY(7)) NOT IN (SELECT c1 FROM t1); -- actual: {}, expected: {a}

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          John Jove John Jove added a comment -

          I also try other variants of the above test cases, which results are as follows.

          -- case 3
          		 
          CREATE TABLE t1 (c1 TEXT, UNIQUE (c1)) ENGINE=InnoDB;
          		 
          INSERT INTO t1 (c1) VALUES ('a');
          		 
          SELECT c1 as r2 FROM t1 WHERE CAST(c1 AS BINARY(7)) NOT IN (SELECT c1 FROM t1); -- {a}


          -- case 4
          		 
          CREATE TABLE t1 (c1 TEXT) ENGINE=InnoDB;
          		 
          INSERT INTO t1 (c1) VALUES ('a');
          		 
          SELECT c1 FROM t1 WHERE CAST(c1 AS BINARY) NOT IN (SELECT c1 FROM t1); -- {}

          John Jove John Jove added a comment - I also try other variants of the above test cases, which results are as follows. -- case 3 CREATE TABLE t1 (c1 TEXT, UNIQUE (c1)) ENGINE=InnoDB; INSERT INTO t1 (c1) VALUES ( 'a' ); SELECT c1 as r2 FROM t1 WHERE CAST (c1 AS BINARY (7)) NOT IN ( SELECT c1 FROM t1); -- {a} -- case 4 CREATE TABLE t1 (c1 TEXT) ENGINE=InnoDB; INSERT INTO t1 (c1) VALUES ( 'a' ); SELECT c1 FROM t1 WHERE CAST (c1 AS BINARY ) NOT IN ( SELECT c1 FROM t1); -- {}
          alice Alice Sherepa added a comment -

          Thanks! I repeated as described on 11.4,11.8, with InnoDB. Myisam returns the expected result

          alice Alice Sherepa added a comment - Thanks! I repeated as described on 11.4,11.8, with InnoDB. Myisam returns the expected result

          People

            psergei Sergei Petrunia
            John Jove John Jove
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              Updated:

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